A ground fault is a significant contributor of electrical faults experienced in many types of electrical equipment. In some operating conditions, such as vehicles operating in damp, wet, and dusty environments, the frequency of ground faults may be increased relative to systems that operate in other conditions. While various regulations mandate inclusion of ground fault detecting devices in electrical systems, failure to test the functionalities of these detecting devices can pose significant safety risks, and result in severe component damage due to arcing and/or fire caused by the ground faults that are not detected in time. Additionally, extended downtime of the electrical equipment can have significant cost impacts on the equipment.
In some vehicles (e.g., rail vehicles such as locomotives), a ground fault typically occurs at inverter load motors and cables. This type of fault may be the result of a loss of insulation. Currently, the ground fault is detected by individually shutting down each of several inverters onboard the vehicle, determining if the ground fault is still present, and eliminating various inverters as the source or cause of the ground fault until the ground fault is not detected when the responsible inverter is shut down. This process typically requires the vehicle to be shut down and stationary, thereby preventing continued use of the vehicle.
In mining vehicles, a ground fault detection circuit trip test can be carried out manually to test whether a ground fault in circuits of the vehicles is detected by ground fault detection hardware of the vehicles. The test may be performed using jumper wire on a 1,000-volt direct current (DC) bus by an elaborate manual sequence of charging and discharging the circuit. The failure to follow the test procedure may cause injury to persons or components.